Yes, opening the door of a refrigerator in a closed room can cool down the room temporarily, but it is not an efficient or practical way to cool a room in the long term.
Refrigerators work by removing heat from the inside and expelling it outside, which cools down the contents inside the fridge. When you open the refrigerator door, the cold air inside the fridge will spill out into the room, causing a brief drop in temperature. However, the refrigerator is not designed to cool a large space like a room, and the cooling effect will be limited to the immediate area around the fridge.
Moreover, the energy consumption of keeping the refrigerator door open will be much higher than the cooling effect it provides. The fridge's compressor will have to work harder to try and maintain the low temperature, leading to increased energy usage.
If you want to cool down a room efficiently, it's better to use an air conditioner, a fan, or open windows to allow natural air circulation. These methods are designed to cool larger spaces effectively and are more energy-efficient than leaving the refrigerator door open.